incidental

1incidental (to something)happening in connection with something else, but not as important as it, or not intendedThe discovery was incidental to their main research.incidental music(= music used with a play or a movie to give atmosphere)You may be able to get help with incidental expenses(= small costs that you get in connection with something).

2incidental to something(technology)happening as a natural result of somethingThese risks are incidental to the work of a firefighter.